There are known ultrasonic processing apparatuses adapted to make a nonwoven fabric containing thermoplastic synthetic fibers or a film of thermoplastic synthetic resin run in the form of a fibrous web in a machine direction and to ultrasonically process such a web in the course of running.
For example, JP S58-39836 U (PTL 1) discloses an ultrasonic processing apparatus including a processing horn energized by ultrasonic oscillations and a pressure roller cooperating with the processing horn. The processing horn and the pressure roller rotationally cooperate with each other to subject a workpiece to ultrasonic processing so that the workpiece may be continuously sealed.
A rotational sealing system disclosed in JP H10-513128 A (PTL 2) includes a drum rotating in a direction in which a workpiece in the form of a fibrous web runs, a first thermal energy input device extending in a cross direction with respect to the rotational direction of the drum and a second thermal energy input device operatively associated with the drum so as to rotate together with the drum and simultaneously to be movable in the cross direction wherein the workpiece is located between the first thermal energy input device and the second thermal energy input device. The second thermal energy input device moves in the cross direction in combination with the first thermal energy input device to impart the workpiece thermal energy in the course of rotation of the drum and, upon completion of thermal energy input, moves away from the first thermal energy input device to its initial position. One of the first and second thermal energy input devices is an ultrasonically oscillating horn and a remainder is an anvil.